This invention relates to techniques for creating “routes” for a manufacturing process flow, and more particularly to creating routes for fabrication processes for semiconductor devices. As used herein, a “route” is a sequential series of manufacturing process steps.
Multiple teams of people are needed to define and create a manufacturing process flow for semiconductor device fabrication. Individuals and groups belonging to these teams are referred to herein as “entities.” These entities include:
(1) Integration Engineer (IE): An entity, also referred to as “requestor”, who knows the final product configuration (that is, what the finished product should look like), and defines the process flow. The IE makes input to the route build process.
(2) Route Builder (RBT): An entity who decides how to execute the processes available to build the product. The RBT assembles individual process steps into the final manufacturing process flow. This entity is not found in all manufacturing environments. In general, however, a fully automated semiconductor fab is so complicated that they have an important task.
(3) Process Engineer (PE): An entity who is responsible for the process tools in which the devices are actually built; that is, individual processes in the overall process flow. The PE is concerned about tool performance (tool setup, checks and feedback), and must monitor and deliver acceptable product yield.
(4) Manufacturing: An entity which carries out processes prescribed by the Route Builders (RBT) by directing automated tools set up by the Process Engineers (PE).
All of the above-named entities are found in a typical semiconductor device manufacturing facility. The present invention is related to how these entities interact with one another to arrive at a valid route for a manufacturing process. The invention will be described in detail below with reference to a process for manufacturing semiconductor chips in a “fab” or fabrication facility.
Each of the entities mentioned above often have different, sometimes conflicting, objectives. For example:
(1) The objective of the Integration Engineer (IE) is to make the highest performance (speed) and yield (quality) chip in the shortest time possible. The IE is prone to try novel combinations of existing and new processes to achieve these objectives.
(2) The objective of the Route Builder (RBT) is to make routes as quickly as possible but the routes must themselves have the highest quality and consistency possible to assure smooth flow of product on the route at time of manufacture. Since there are many IE entities requesting routes for different purposes, it is the responsibility of the RBT to decide where route sub-units can be shared and thus have assured consistency across the customer set.
(3) The objective of the Process Engineer (PE) is to create processes in the fab that have high quality and reliability and that do not harm the fab, such as by damaging the tools or causing slowdowns. Poor ordering (sequencing) of process steps can result in damage to the tools. The PE sometimes has to impose limitations upon the IE with regard to experimenting with new or modified processes.
(4) The objective of Manufacturing is to process the product on the route as quickly as possible. Manufacturing typically does not consider the yield impacts in their efforts to expedite the processing of the product.
It is important to implement a system for communication among these multiple entities to define an acceptable manufacturing process flow. However, the input phase of the route creation activity is typically uncontrolled and based largely on ad hoc communications (e.g. email) among the various entities. In many instances, multiple emails with spreadsheets are exchanged between the entities. For example, when the Manufacturing Execution System (MES) SiView is used, a typical email communication is a modified equipment relation flow report from SM (specification manager, part of SiView) copied into a spreadsheet. The result of this practice is that too much information is given on some aspects of the route, and not enough on others. Generally, no consistency in the information required to build the route is enforced by the route builder (RBT) or requestor (IE). Such ad hoc communication solutions are not efficient and not appropriate in a high cost and possibly fully automated manufacturing environment. Accordingly, there is a need for a system for facilitating agreement among the various entities regarding the ordering and content of process steps.